This invention relates to a printed circuit board provided with at least one component having one or more leads which are secured to contact faces of the printed circuit board. The invention also relates to a method of mounting a component having one or more leads on a printed circuit board, at least one lead of the component being secured to the surface of a contact face of the printed circuit board.
Customary printed circuit boards comprise an electrically insulating substrate on which and/or in which a pattern of electroconductive tracks is provided. A number of these tracks terminate at a contact face situated at or on the surface of the printed circuit board. Electric components, such as resistors and capacitors, are secured to such contact faces by means of their terminals. In its most elementary form, such an electric component may consist of a single, electroconductive wire which is connected, for example, to an antenna or to another electric or electronic component which is connected to the printed circuit board via this wire. Resistors and capacitors generally comprise two or more terminals.
As regards the above-mentioned electric components, generally two embodiments are distinguished. Such components may take the form of leaded components or of leadless, surface-mountable components (SMD components). When leaded components are provided, the leads are customarily passed through the printed circuit board and subsequently secured to one or more contact faces of the printed circuit board by means of a soldered joint. To place SMD components on the printed circuit board, use is customarily made of a glued joint. Subsequently, the connection faces of the components are electrically connected to the contact faces of the printed circuit board by means of a wave-soldering treatment. The SMD embodiment of components is generally more expensive than the leaded embodiment.
Printed circuit boards are frequently provided with a plurality of surface-mountable components and one or a few leaded components. In this case, one or more through-holes are formed in the printed circuit board for the leaded components. In practice, it has been found that positioning and forming the necessary through-holes as well as individually securing the leads by soldering are operations which are very objectionable from the point of view of costs. This applies, in particular, if both leadless and leaded components must be provided on the PCB.